Funds are requested to purchase a commercial Proteomics analysis LC-MS/MS system dedicated for biological experiments where protein identification, protein quantification, and time-resolved analysis of proteome profiling, and post-translation modification are currently in progress. The new LC-MS/MS system will be housed at the Proteomics and Biological Mass Spectrometry Facility (PBMS facility) at the University of Connecticut Health Center. This research center offers use of highly sensitive micro-capillary liquid chromatography-coupled to Tandem Mass Spectrometry instrumentation and proteomics related resources to the research community at the UCHC. It is anticipated that many of the over 20 laboratories and over 30 graduate and postdoctoral students using the PBMS facility will employ capabilities of the sensitive LCMS/ MS system to advance the wide range of research programs. Projects from 5 major users with well developed projects at the UCHC are described here. All of these requires the sensitive and rapid protein identification and simultaneous quantification afforded by the Finnigan LCQ-XP ion trap technology coupled to the parallel-computer database analysis by the use of uniquely available SEQUEST, XPRESS, INTERACT, and Proteome 3D software tools. Dr. David Han will utilize 3D-ICAT technology to identify and quantify apoptotic signaling proteins and engulfment ligands that are presented on apoptotic cell membranes by differential ICAT labeling. Dr. Timothy Hla will analyze proteomics changes that are direct result of the EDG1 - receptor deletion or COX-2 enzyme overexpression using mouse models. Dr. Dan Wu will analyze membrane and cytosolic proteomics changes that are induced by Wnt protein and chemo-attractant signal transduction. Dr. Glen King structure biology colleagues will utilize mass spectrometry to delineate structure-function studies of multiple protein complexes. Dr. Bruce Mayer will utilize mass spectrometry to identify SH2 interacting proteins. Opening of a new academic research building in 1999 and recruitment of over 40 new faculty members at the UCHC, the increase in funding of over 40 million from 1996-2002, the recent award of a Program Project grant application that utilize proteomics technologies, and significant publications utilization proteomics technologies attest to the need for an additional new Proteomics Workstation at the University of Connecticut Health Center.